I know sd1 and possibility, and you know that in pa2x you can merge 6 layer of wav drum in each note ? of course in sd1 was nice 1 only too. the first aswer from ketron after this question was: "for what you need it ?, you have the audio drum".. ok understand but... you can infinite discussion with them is logical that they try to see in future only audio drum
if you whant more memory I hope some days and go out the expansion of Aj, thare are styles, audio, sounds, and memory too, plus some bugs correction if install hardware modification
about crash: do you remember the first super drum kit (3 kit) before the first and second pen upgrade ? there was big fantastic sounds stereo like crash, ride, snare ecc that r. messier post demo in ketorn site. then after the first pen upggrade they killed it, because need space. after my question for put it or put it in .ins format ... the answer was that no body use it then nothing. (but they was very good for remix midi styles. of course I hope for .ins and wav for user drum kit too but very very difficult